1. Field of the Invention
The invention relates to a fluid line with a pipe, a connector, which has a pipe connection and which is arranged on one end of the pipe, and a heater, which is arranged in the interior of the pipe.
2. Discussion of Background Information
The invention is described below based on a fluid line which is used in a motor vehicle to guide urea from a tank to a consumption point, for example, a pump. Urea is used with diesel engines in order to reduce the nitrogen oxides.
In the case of low outdoor temperatures of below −11° C. there is a danger that the urea will freeze in the fluid line and thus a conveyance of the urea through the line is no longer possible. In the case of other liquids, the freezing points can have different values. If the liquid freezes, in any case a transport of the liquid through the fluid line is no longer possible.
It has therefore been proposed to heat the fluid line and optionally the connector as well. One way of doing this is to wind a heating wire around the pipe and around the connector which, when it is loaded with a corresponding current strength, generates heat that can be transmitted through the pipe to the liquid located in the interior of the pipe. However, an embodiment of this type has the disadvantage that the heater is exposed to the risk of damage due to external influences. Furthermore, most of the heat generated by the heater is not transmitted to the liquid in the interior of the pipe, but is irradiated to the outside.
Another suggestion is to embody a heating conductor in a flat manner and to shape it in a helical manner and then to arrange it in the interior of the pipe. Although a relatively large surface is available here for the heat transfer from the heater to the liquid, a flat heating conductor is very sensitive and can already be damaged during assembly. Furthermore, it is relatively difficult to bring the electric power that is required for generating the heat to the heating conductor.